1. Field of the invention
The present invention relates to one-piece closures having radially depressable child-resistant means adapted to release a top lid member from a bottom lid member.
2. Description of the prior art
One-piece closures are known in the prior art and use a bottom member adapted to engage the neck portion of a container and a top lid member adapted to seal the container when in the closed position. The two members are fixedly attached by hinge means located at the rear of the closure such that the top lid member is free to rotate from a closed to an open position. The hinge means may either be a continuous strap connecting the members, a strip hinge or a unitary hinge adapted to hold the top lid member in either of a closed or fully open position. Such closures are widely used as dispensing closures for various liquids--because of their low manufacturing cost and customer acceptance--by providing the bottom skirt member with a planar end skirt to close the container and providing the planar end with a dispensing orifice, but the closures cannot be adapted for use on containers holding products where a child-resistant closure must be used. The Poisoning Prevention Packaging Act of 1970 stipulates that certain substances such as medicines, for example, be packaged in special (child-resistant) packaging and sets forth protocols to evaluated such packaging. Under the aforementioned Act, dispensing closures cannot be used on containers holding the listed substances because they fail the standard protocols.
It is known in the prior art to provide unitary closures with child-resistant means so that the closures may be used with special packaging. U.S. Pat. No. 4,209,100 to Uhlig discloses a resiliantly flexible portion of the bottom member skirt that ordinarily blocks access to the top lid, but, when pressed radially inward allows the user to insert a finger-nail between the bottom and top members and pry the top lid member open. It has been noted in several studies however, that even small children are adept at performing simple tasks.
It is also known in the prior art to provide a latch assembly between the lid and bottom members of a unitary closure to hold the lid member in a closed position. The latch assembly includes a hook on the terminus of a moveably attached resiliantly flexible member on one of the members of the closure such that the hook engages thereover a ledge formed on the other of the members to hold the top lid member in a closed position. It is known to provide such a resiliantly flexible member with a hook attached to the lid member such that the resilient portion must be pressed radially inward to disengage the hook from a ledge on the bottom portion as shown by U.S. Pat. No. 4,244,495 to Lorscheid et al., and U.S. Pat. No. 4,170,315 to Dubach et al.
A resilient member that operates in the same manner but which must be pulled radially outward to disengage the hook is shown by U.S. Pat. No. 4,022,352 to Pehr and U.S. Pat. No. 4,533,058 to Uhlig.
Another method of providing a unitary closure with a resiliantly flexible member is known, in the prior art as illustrated by U.S. Pat. No. 4,629,081 to McLaren. McLaren employs a resiliantly flexible portion of the bottom member skirt that is held in a radially outer position by an annular ring formed on the neck of an associated container. The closure may be rotated to a particular angular alignment wherein a gap in the annular ring allows the flexible member to be depressed disengaging the hook portion. However, child-resistant closures that employ a specially designed container limits their marketability.
It is also known in the prior art to provide a resiliantly flexible member that is not fixedly attached to either member of the closure rather articulates the flexible member thereto via a live hinge instead allowing the perpendicular portion of the hook to be formed parallel to the axis of the closure. U.S. Pat. No. 4,787,526 to Pehr illustrates such child-resistant means. Pehr discloses a member that may be formed at a right angle to the axis of the closure and thereafter folded to the child-resistant position. In the child-resistant position, the bottom portion of the flexible member abuts a second surface so that the hook is held in an outward position until inward pressure applied to the flexible portion bends it over the top of the second surface releasing the hook. One problem with this procedure is that the finger or thumb that is used to bend the hook backwards interferes with pulling up on the lid. Too, once open, the flexible portion rotates downward into an inoperable position, so the user must fold the hook back into the CR position before closing. CR means of this type are referred to as `active` by the CR manufacturing industry (ie. requiring the user to do something to achieve CR) thus limiting their use.